It depends on what you believe a dream guide's composition is. Some believe that they are beings that will show themselves to you when they have deemed you worthy (or at other times). Others (like me) believe that they are simply DCs that you put your focus and belief in that what they say is true and that they will stay persistent (like a persistent realm), no mysticism, just a fun way around some barriers, which is what I believe that LDing is... breaking mental barriers and creating pathways instead of road blocks.

The first would be impossible to create, but you could "make desirable conditions"
The second is believing that all DGs are your creation.